This invention relates to control of vibratory/oscillatory mixers and other vibratory/oscillatory systems. In particular, the invention relates to control of such systems at an optimal or peak efficiency point based on displacement, velocity, acceleration, or jerk operating points.
The mixing of fluids involves the creation of fluid motion or agitation resulting in the uniform distribution of either heterogeneous or homogeneous starting materials to form an output product. Mixing processes are called upon to affect the uniform distribution of: miscible fluids such as alcohol in water; immiscible fluids such as the emulsification of oil in water; particulate matter such as the suspension of pigment particles in a carrier fluid; mixtures of dry materials with fluids such as sand, cement and water; thixotropic (pseudo plastic) fluids with solid particulates; the chemical ingredients of pharmaceuticals; biological specimens, such as bacteria, while growing in a nurturing media without incurring physical damage; solid-solid mixing such as dry powders, coating of materials, dispersion of nanoparticles in either dry or wet medias, and reacting mixtures.
Mixing may be accomplished in a variety of ways: rotating impeller(s) mounted on shaft(s) immersed in the fluid mixture agitate(s) the fluid and/or solid materials to be mixed, or a translating perforated plate accomplishes the agitation, or the vessel itself containing the materials is agitated, shaken or vibrated. Mixing may be continuous (as when a rotating impeller is used or the containing vessel is vibrated) or intermittent as when the drive mechanism starts and stops in one or several directions. A static mixer is a type of continuous system that is a flow through device. The continuous flow device may also be vibrated to mix the materials as they flow through.
With a conventional vibrational mixer, the amplitude of mixing can be varied within very narrow limits, and the frequency is generally set at the frequency of the alternating current (AC) power source. Even when using a motor controller with frequency control, the vibrational frequency of a conventional vibrational mixer can be varied only within relatively narrow limits. Mixing at the natural resonant frequency of the mechanism is usually avoided due to the high loads and associated wear of the mechanisms.
The background art is characterized by U.S. Pat. Nos. 4,142,804; 4,610,546; 4,860,816; 4,930,898; 5,033,321; 5,069,071; 6,431,790; 6,491,422; 7,270,472; 7,481,918; and 7,726,871; and U.S. Patent Application Nos. 2002/0118594; 2007/0280036; 2009/0245015; and 2010/0054076; the disclosures of which patents and patent applications are incorporated by reference as if fully set forth herein.
The background art also is characterized by U.S. Pat. Nos. 2,911,192; 2,975,846; 3,004,389; 3,375,884; 3,379,263; 3,461,979; 3,477,237; 3,572,139; 3,633,688; 3,736,843; 3,741,315; 4,150,568; 4,330,156; 4,384,625; 4,693,325; 4,836,299; 4,527,637; 5,004,055; 5,141,061; 5,417,290; 5,540,295; 5,549,170; 5,562,169; 6,129,159; 6,736,209; 6,863,136; 7,191,852; 7,234,537; and 7,341,116; and U.S. Patent Application Nos. 2006/0157280 and 2007/289,778; the disclosures of which patents and patent application are incorporated by reference as if fully set forth herein. The background art is also characterized by WO/2001/83933.